Conventionally, a predetermined liquid medicine or blood and the like are supplied internally to the body of a patient by using a plurality of liquid transfusion tubes. In such a case, the tubes are communicated with each other by using connectors each attached to one end of each tube to connect each other. A male luer connector is attached to a tube upstream the flow of the liquid and a female luer connector attached to a tube downstream. The male luer connector is treated to remove gases such as air contained therein together with the upstream tube and only a liquid such as liquid medicine is filled in the connector before connecting to the female connector.
The liquid is flowed from the tube into the male luer connector while a cap including an air filter that does not allow to flow the liquid but gas is attached to the tip of the male luer connector, thereby removing only the gas contained in the liquid out by passing through the air filter (see, for example, Japanese Patent Unexamined Publication No. 2005-535379). The cap attached to the male luer connector comprises a lid attached to a generally cylindrical body, the lid having a pathway communicated with the body, a cylindrical absorbing member attached along the inner peripheral surface of the body, and an air filter provided within the pathway of the lid.
Therefore, when the liquid such as liquid medicine is supplied from the tube into the male luer connector with this cap attached thereto, if there is an air layer between the liquid, the liquid that firstly enter the cap is absorbed by the absorbing member and, then, the air is discharged to the exterior through the air filter. Thus, within the male luer connector, only the liquid not containing the air is filled therein.
However, since the amount of the liquid to be absorbed by the absorbing member is limited in the cap of the conventional male luer connector described above, when an amount of the liquid cannot be absorbed by the absorbing member before removing the air layer, the air that remained within the male luer connector raises a problem. Also, there is a problem that the operation for removing the air in such a case would be complicated.
In the light of the problems described above, the object of the invention is to provide a cap for a connector which can fill a male luer connector with only a liquid such as liquid medicine without any gases such as air remaining in the male luer connector.